Where did the doctrine of eternal punishment come from?
Did Jesus believe in or teach this?
Don Rogers has a WONDERFUL post about this doctrine at his place.
A sample of what you’ll find there is:
“We should bear a fact in mind. When the doctrine of endless punishment began to be taught in the Christian Church, it was not derived from the Scriptures, but from the heathen converts to Christianity, who accepted Christ, but who brought with them into their new church that doctrine which had for centuries been taught in heathen lands, but which neither Moses nor Christ accepted. And having received the idea from heathen tradition, it was natural that the early Christians should transfer it to the Bible, and seek to find it there.”
It’d be well worth your time to go read the rest at Don’s place.